白内障手术后后囊膜混浊的量化比较

目的 评估白内障术后疏水件丙烯酸人工晶状体SensarAR40e和硅胶人工晶状体的后囊膜混浊(PCO),并用能客观评估PCO的软件量化分析.方法 共选择98只眼行标准的超声乳化白内障吸除术,人工晶状体囊袋内固定.所有眼随机植入Sensar AR40e或硅胶人工晶状体,但同一患者植入的人工晶状体必须不同.在第1年和第2年时后照法拍摄后囊膜图像,通过去除浦肯野反光、增强对比度、过滤后增强低密度的PCO等方法处理后用POCO软件分析对比.结果 术后1年疏水性丙烯酸人工晶状体PCO为(0.32±0.13)%硅胶人工晶状体为(0.39±0.17)%(P=0.37).2年时疏水性丙烯酸人工晶状体PCO为(0.42±0.20)%,硅胶品状体为(0.34±0.18)%(P=0.50).患者术后1年,2年时疏水性丙烯酸人工品状体PCO的严重级别分别是(0.50±0.30)和(0.82±0.58),‘亏硅胶人工晶状体的(0.63±0.35)和(0.55±0.35)相比,无统计学意义(P＜0.05).结论 PCO后囊膜混浊量化分析系统提供了客观而且可重复性强的量化PCO的方法,也是研究预防PCO技术的有力工具.     

疏水性和肝素修饰亲水性丙烯酸酯人工晶状体的临床应用效果对比

目的比较疏水性丙烯酸酯人工晶状体(intraocular lens,IOL)与肝素修饰的亲水性丙烯酸酯IOL的临床应用效果。方法 121例(152眼)白内障患者接受了白内障超声乳化摘出联合IOL植入术,其中64眼植入疏水性Sensar AR40e丙烯酸酯IOL为Sensar AR40e组,88眼植入肝素修饰的亲水性HQ201hep丙烯酸酯IOL为HQ201hep组。记录并比较2组术后3d裸眼视力、术后2a最佳矫正视力及后囊膜混浊(posterior capsular opacification,PCO)的发生情况。结果 2组间术后3d裸眼视力及术后2a最佳矫正视力的差异均无统计学意义(χ2=1.066、1.912,P=0.785、0.591)。术后2a PCO的发生率,Sensar AR40e组为15.63%(10/64),HQ201hep组为21.59%(19/88);2级和3级PCO的发生率Sensar AR40e组为1.56%(1/64),HQ201hep组为7.95%(7/88),2组间比较差异均无统计学意义(χ2=3.118、3.036,P=0.374、0.081)。进一步分析发现,在2组60岁以上患者的148眼中,Sensar AR40e组的1.56%(1/64)和HQ201hep组的3.57%(3/84)发生了2级或3级PCO,2组比较差异无统计学意义(χ2=0.055,P=0.814);Sensar AR40e组1.56%(1/64)和HQ201hep组2.38%(2/84)接受了Nd:YAG激光后囊膜切开术,2组比较差异无统计学意义(χ2=0.000,P=1.000)。结论疏水性丙烯酸酯IOL与肝素修饰的亲水性丙烯酸酯IOL植入术后的视力和PCO程度无统计学差异。     

两种人工晶状体植入术后发生后囊膜混浊情况的Meta分析

目的：：系统评价AcrySof直角方边人工晶状体和Sensar前圆后方人工晶状体对术眼后囊膜混浊的预防作用。方法：计算机检索PubMed (1980/2015-09)、CBM (1990/2015-09)、VIP (1989/2015-09)、CNKI (1990/2015-09)和wanfang Data(1990/2015-09),收集年龄相关性白内障超声乳化联合植入 AcrySof 三片式人工晶状体与植入Sensar三片式人工晶状体术后后囊膜混浊发生情况的随机对照试验,由两名评价者按照纳入与排除标准筛选研究、提取资料和质量评价后,采用RevMan 5.2软件进行Meta分析。结果：共纳入5项研究,总计1036眼( AcrySof组553眼, Sensar组483眼),随访时限6mo~2a,Meta分析结果显示：(1) AcrySof 组术后 PCO 发生率显著低于 Sensar 组(OR=0.67,95%CI：0.45~0.99,P=0.04);(2)两种人工晶状体植入后术眼后囊膜Nd：YAG激光切开术施行率比较,无统计学差异(OR=0.57,95%CI：0.32~1.02,P=0.06)。(3)2 a 以上长期随访亚组分析中, AcrySof 组PCO发生率显著低于Sensar组( OR=0.60,95%CI：0.40~0.91,P=0.02),两组人工晶状体术后后囊膜激光切开术施行率比较,无统计学差异( OR=0.60,95%CI：0.33~1.09,P=0.09)。结论：AcrySof三片式人工晶状体相比于Sensar三片式人工晶状体显示出较强的预防后囊膜混浊作用。     

不同材料的人工晶状体植入术后的临床疗效观察

目的　评价超声乳化白内障吸出联合不同材料制成的人工晶状体植入术治疗白内障的疗效。方法　将 14 5例(14 8眼 )行超声乳化白内障吸出联合人工晶状体植入术的患者分为 3组 ,术中随机植入PMMA人工晶状体、新型疏水性丙烯酸酯类、硅凝胶类折叠式人工晶状体。比较术前和术后视力、散光情况。统计术后晶状体后囊膜混浊情况及行Nd :YAG激光后囊膜切除术的情况。结果　术后早期视力、3个月后散光度数、晶状体后囊膜混浊发生率及行Nd :YAG激光后囊膜切除术的情况 ,植入折叠式人工晶状体者均优于植入非折叠式人工晶状体者。植入Canonstaar硅凝胶类折叠式人工晶状体组术后散光最小。植入AcrysofTM新型疏水性丙烯酸酯类折叠式人工晶状体组术后晶状体后囊膜混浊发生率及行Nd :YAG激光后囊膜切除术的比例最低。结论　超声乳化白内障吸出联合折叠式人工晶状体植入的临床应用效果满意。     

Sensar人工晶状体植入术后的临床观察

目的观察和评估白内障超声乳化植入Sensar人工晶状体的临床效果。方法对92例（106只眼）年龄相关性白内障,应用表面麻醉颞侧透明角膜切口,行白内障超声乳化吸除联合Sensar人工晶状体植入术。观察术后视力、术后眩光、人工晶状体在晶状体囊袋内的位置及后囊膜的混浊等的变化。结果术后观察12～28个月,平均19.4个月,最佳矫正视力≥0.5者达100%,≥1.0者67眼（占63.21%）,患者在日常生活中无视物不适,无眩光,人工晶状体居后囊中央,与后囊膜紧贴,后囊膜平展,Ⅰ级后囊膜混浊95眼（89.62%）,Ⅱ级后囊膜混浊9眼（8.49%）,Ⅲ级后囊膜混浊2眼（1.89%）。结论Sensar人工晶状体植入术后视物舒适,能减少眩光,能减少后发性白内障。     

负度数人工晶状体植入术治疗白内障合并超高度近视眼

目的 观察白内障超声乳化联合负度数Sensar AR40e折叠式人工晶状体植入治疗超高度近视合并白内障的临床疗效.方法 对超高度近视合并白内障行超声乳化白内障吸除联合负度数Sensar AR40e人工晶状体植入术的35例(59只眼)患者进行回顾性研究,记录术前眼轴长度,观察手术并发症和术后视力、屈光度数及其与预期屈光度数的偏差值(屈光度数偏差值).术后随访时间为3～12个月.结果 术前平均眼轴长度为31.34mm.术后最佳矫正视力≥0.2共49只眼(83.05%),≥0.5者共26只眼(44.07%).术后屈光度数偏差值＜±1.00 D共31只眼(52.54%),<±2.00 D共52只眼(88.14%).术中仅1只眼晶状体后囊膜破裂;术后6只眼晶状体后囊轻度混浊,随访期间无视网膜和脉络膜脱离.结论 白内障超声乳化联合负度数人工晶状体植入术治疗白内障合并超高度近视眼安全、有效.植入负度数后房型人工晶状体既可以维持眼内组织的稳定性,又可同时进行屈光矫正.     

新一代疏水性丙烯酸人工晶状体临床应用观察

目的:观察和评估新一代疏水性丙烯酸人工晶状体SensarAR40e的临床应用疗效及与硅胶人工晶状体的比较。方法:对46例(92眼)白内障患者行超声乳化吸除人工晶状体植入手术,1眼植入SensarAR40e人工晶状体,另1眼植入新型硅胶人工晶状体。观察SensarAR40e人工晶状体的植入性能、术中并发症、术后视力、术后前房反应、人工晶状体位置、后发障及以上指标与硅胶人工晶状体的对比情况。随访时间为6mo。结果:术后1wk,平均裸眼远视力为0.57±0.20,术后1,3,6mo,平均最佳矫正远视力分别为0.81±0.16,0.77±0.19,0.71±0.25;术后前房反应轻微;术后3,6mo,SensarAR40e人工晶状体眼后发障眼分别为2,4,硅胶眼则为4,12;未发现人工晶状体明显移位者。结论:SensarAR40e人工晶状体具有良好的植入性能、光学中心定位性能,术后反应轻,后发障发生率低,手术疗效满意。     

白内障术中后囊连续环形撕囊预防后囊混浊的临床观察

目的 探讨白内障囊外摘除联合人工晶状体植入术中行后囊膜连续环形撕囊(PCCC)对预防术后后囊混浊(PCO)的作用。方法 对365例(426只眼)白内障行常规囊外摘除后行后囊膜连续环行撕囊再植入人工晶状体。结果 365例(426只眼)后囊膜连续环形撕囊均成功，人工晶状体植入囊袋中。术后随访2～3年后囊混浊未见发生。结论 在白内障囊外摘出后对后囊膜连续环形撕囊是可行的，它避免了后囊混浊产生的根本原因，对人工晶状体植入后视力无明显影响。     

两种不同材料折叠人工晶状体植入术后后发障的临床观察

为探讨人工晶状体(IOL)材料与后囊膜混浊(PCO)发生的关系,我们随访了门诊施行超声乳化白内障摘除术(PHACO)联合疏水性丙烯酸IOL(AcrySof)或疏水性硅凝胶IOL(CeeOn911A)植入的患者术后一年PCO的发生情况。一、材料和方法选择2002～2004年在北京协和医院和澳门仁伯爵医院老年性白内障患者中行PHACO术联合疏水性AcrySofIOL或疏水性硅凝胶CeeOn911AIOL两种不同材料折叠IOL植入的病例;除外合并糖尿病、高度近视、青光眼、葡萄膜炎等患者。随访资料完整、手术中顺利将IOL植入囊袋内且随访时间达一年的患者119例(137眼)。其中植…     

不同丙烯酸材料的人工晶状体对后发性白内障的影响

目的 探讨三种不同的丙烯酸材料的人工晶状体应用于白内障超声乳化吸除联合人工晶状体植入术后对后发性白内障的影响作用.方法 超声乳化白内障吸除联合人工晶状体植入术的960例白内障患者(964只眼),Sensar组310只眼,Acrysof三片组332只眼,Acrysof一片组322只眼,术后定期随访18～28个月,观察视力、后发性白障的发生情况.结果 术后随访24月时,发生1级以上后囊膜混浊SensarIOL组的发生率(13.5%),明显高于Acrysof一片式IOL组及Acrysof三片式IOL组的发生率(7.5%,3.7%).经卡方检验,P值均<0.05,有显著性差异,而Acrysof三片式IOL组后囊膜混浊的发生率较Aerysof 一片式IOL组高,P<0.05.结论 AcrySof丙烯酸式一片式人工晶状体植入后出现后发性白内障的发生率在三组中最低.可以减少后发性白内障的发生降低Nd:YAG激光的使用率,提高手术效果,是现代白内障手术可选择的理想的人工晶状体.     

Hydrophobic acrylic and plate-haptic silicone intraocular lens implantation in diabetic patients: pilot randomized clinical trial

PURPOSE: To compare the capsular and uveal reaction after implantation of a plate-haptic silicone intraocular lens (IOL) (C11UB, Chiron) and a hydrophobic acrylic (AcrySof MA60, Alcon) IOL in diabetic patients. SETTING: Moorfields Eye Hospital and St. Thomas' Hospital, London, United Kingdom. METHODS: Thirty-five diabetic patients were recruited consecutively and randomly assigned to have implantation of either of the 2 IOLs. The percentage area of posterior capsule opacification (PCO), anterior capsule contraction (ACC), and postoperative inflammatory indices (flare and cells) were assessed objectively at 2 to 3 weeks, 6 months, and 1 year. Between-group and within-group analyses were conducted using the Student t test or Mann-Whitney test and Friedmann test, respectively. RESULTS: Between-group analysis showed the percentage area of PCO was significantly greater in patients with plate-haptic silicone IOLs at 6 and 12 months (P = .002). At 6 months, ACC was significantly greater in the plate-haptic group (P = .04), but the difference was not significant at 12 months. There was higher flare in the hydrophobic acrylic IOL group than in the plate-haptic silicone IOL group at 2 to 3 weeks (P = .08). Within-group analysis showed that over the follow-up period, the plate-haptic silicone group, but not the hydrophobic acrylic group, had a progressive increase in PCO (P = .003). In the hydrophobic acrylic group, but not the plate-haptic silicone group, there was a significant reduction in the mean anterior chamber flare value (P = .01). There was no significant difference in visual acuity or contrast sensitivity at any postoperative visit. CONCLUSION: In diabetic patients, hydrophobic acrylic IOLs can lead to an increased flare in the early postoperative period but they seem to be more favorable than plate-haptic silicone IOLs because the latter lead to more PCO.     

Optical coherence tomography of intraocular lens implants and their relationship to the posterior capsule: a pilot study comparing a hydrophobic acrylic to a plate-haptic silicone type

BACKGROUND: Optical coherence tomography (OCT) has been used to examine the anterior as well as the posterior segment and can be used to examine the intraocular lens (IOL) and their relationship to the posterior capsule in vivo. OBJECTIVES: To use OCT to examine two of the IOLs and some of the features related to the development of posterior capsular opacification (PCO). METHODS: This is a pilot study of a prospective (n = 12) and a retrospective (n = 14) series of patients who had uneventful phacoemulsification and IOL implantation of either hydrophobic acrylic (Acrysof; Alcon) or plate-haptic (PH) silicone (C11UB; Chiron, Bausch & Lomb) IOLs. The outcome of interest was the ability of OCT to clearly delineate the outline of the IOL optics and their appositional relationship to the posterior capsule. RESULTS: OCT showed that hydrophobic acrylic IOLs had a better defined outline than PH silicone IOLs. It also showed close apposition between hydrophobic acrylic optics and the mid-peripheral part of the posterior capsule and the absence thereof with PH silicone IOLs. CONCLUSIONS: Hydrophobic acrylic implants have better definition on the OCT scans than PH silicone and they develop close apposition to the posterior capsule. The latter feature is consistent with the 'no space, no cell, no PCO' concept and what is known about the effect of the implant material and design on the rate of PCO.     

Effect of intraocular lens optic edge design and material on fibrotic capsule opacification and capsulorhexis contraction

PURPOSE: To examine the influence of intraocular lens (IOL) optic edge design and optic material on fibrosis of the anterior and peripheral posterior capsules and on capsulorhexis contraction. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: This randomized controlled patient- and examiner-masked study comprised 210 eyes of 105 patients with bilateral age-related cataract. In Group 1 (n = 53), the Sensar OptiEdge AR40e hydrophobic acrylic IOL with a sharp posterior optic edge was compared with the AR40 acrylic IOL with a round edge. In Group 2 (n = 52), the ClariFlex OptiEdge silicone IOL with a sharp posterior optic edge was compared with the PhacoFlex SI-40 silicone IOL with a round edge All IOLs were manufactured by Advanced Medical Optics, Inc. Standardized digital slitlamp images of anterior capsule opacification (ACO) and fibrotic posterior capsule opacification (PCO) were taken 1 year postoperatively, and digital retroillumination images were taken at 1 week and 1 year. The intensity of fibrotic PCO was graded subjectively (score 0 to 4), ACO was graded objectively (score 0% to 100%), and the capsulorhexis area (mm(2)) was determined objectively. RESULTS: One year after surgery, the mean ACO score was 32% in eyes with the sharp-edged acrylic IOL and 29% in eyes with the round-edged acrylic IOL (P<.05). In the silicone group, the mean was 31% and 26%, respectively (P<.05). The mean fibrotic PCO score was lower in eyes with a sharp-edged acrylic IOL than in eyes with a round-edged acrylic IOL (0.26 and 0.93, respectively; P<.05) and in eyes with a sharp-edged silicone IOL than in eyes with a round-edged silicone IOL (0.24 and 0.82, respectively; P<.001). At 1 year, the mean capsulorhexis area was statistically significantly smaller in eyes with a sharp-edged silicone IOL than in eyes with a round-edged silicone IOL (P<.05). CONCLUSIONS: Acrylic and silicone IOLs with the sharp OptiEdge design led to significantly less fibrotic PCO but more ACO than round-edged acrylic and silicone IOLs. The sharp-edged silicone IOL caused significantly more capsulorhexis contraction than the round-edged silicone IOL and both acrylic IOLs.     

Optical coherence tomography evaluation of posterior capsule opacification related to intraocular lens design

PURPOSE: To evaluate posterior capsule opacification (PCO) and the impact of different intraocular lens (IOL) models on PCO characteristics using optical coherence tomography (OCT). METHODS: Eighty-three eyes with PCO (fibrosis or pearl type) and 32 pseudophakic eyes without PCO were included. Horizontal 3.0 mm long OCT scans of the posterior capsule were obtained. Measurements and means of the peak posterior capsule intensity (PCI) and posterior capsule thickness (PCT) (distance between 2 spikes at posterior capsule) at 3 scan points were recorded. The PCI and PCT were compared with best corrected visual acuity (BCVA) and IOL data. RESULTS: The PCT was high for IOLs with a rounded edge (P = .001) and with poly(methyl methacrylate) (PMMA) IOLs (P<.001). If the IOL optic was concave-convex, the PCT was higher than if the optic was biconvex (P = .001). The PCT of hydrophilic acrylic IOLs was higher than of hydrophobic acrylic IOLs (P = .04). Multivariate analysis of PCT showed that PMMA was the only factor statistically associated with PCT (P = .02). The worse logMAR BCVA correlated significantly with a higher PCT value (P<.001) but not with PCI (P = .42). An IOL size of 12.5 mm was related to fibrosis-type PCO (odds ratio, 3.14; P = .04). CONCLUSIONS: The PCT was most affected by IOL characteristics. Poly(methyl methacrylate) IOLs and IOLs with rounded edges were associated with higher PCT. Hydrophilic acrylic IOLs were associated with greater PCT than hydrophobic IOLs. Posterior capsule thickness was a factor in decreased BCVA.     

The effect of lens edge design versus anterior capsule overlap on posterior capsule opacification

PURPOSE: To determine whether lens edge design or anterior capsule overlap on the intraocular lens (IOL) has greater effect on posterior capsule opacification (PCO). DESIGN: Retrospective cohort clinical study. METHODS: Retrospective. SETTING: Academic clinical practice. PATIENT POPULATION: The patient population consisted of 259 uncomplicated surgical patients (259 eyes) with no confounding comorbidity and at least 1 year of follow-up after surgical placement of a silicone or hydrophobic acrylic lens. OBSERVATION PROCEDURES: Digital retroilluminated photographs were taken to ascertain PCO, anterior capsular opacification (ACO), previous neodymium:YAG capsulotomy and degree of anterior capsule overlap on the IOL optic. MAIN OUTCOME MEASURES: PCO, ACO, YAG capsulotomy rate, and anterior capsule overlap on the IOL optic. RESULTS: One hundred forty-eight digital images (74 silicone and 74 acrylic) were measurable for both anterior capsule overlap and PCO. Complete 360 degrees of anterior capsule overlap on the IOL was associated with decreased PCO (P = <.001). A significant negative correlation was found between the degree of anterior capsule overlap and PCO (P = <.001). Evaluation of PCO, and YAG capsulotomy rates were similar between acrylic and silicone lenses. Minimal anterior capsule overlap may also be associated with PCO prevention. CONCLUSIONS: Implanting a lens with complete anterior capsule overlap on the IOL was found to significantly reduce PCO, which advantage appeared to be greater than PCO prevention by a truncated, sharp edge IOL design.     

Uveal and capsular biocompatibility of hydrophilic acrylic, hydrophobic acrylic, and silicone intraocular lenses.

PURPOSE: To evaluate the long-term response of 6 types of 3-piece intraocular lenses (IOLs) by assessing the cellular reaction on the anterior IOL surface, the behavior of posterior and anterior capsule fibrosis, and flare. SETTING: Department of Ophthalmology, Medical School, University of Vienna, Vienna, Austria. METHODS: One hundred eighty eyes were prospectively randomized to receive 1 of 6 IOLs: hydrophilic acrylic Hydroview (Bausch & Lomb) or MemoryLens (ORC); hydrophobic acrylic AcrySof MA60BM (Alcon) or AMO Sensar AR40 (Allergan); hydrophobic silicone CeeOn 920 or CeeOn 911A (Pharmacia). The patients had standardized cataract surgery, postoperative medication, and follow-up. One year after surgery, 155 eyes were assessed. The cellular reaction was evaluated by specular microscopy of the anterior IOL surface. Anterior and posterior capsule opacification (PCO) was assessed semiquantitatively by biomicroscopy. Flare was measured with a Kowa FC-1000 laser flare-cell meter. RESULTS: Regarding uveal biocompatibility, the hydrophobic acrylic IOLs showed the highest incidence of late foreign-body cell reaction (AcrySof, 30%; AR40, 17%) followed by the hydrophilic acrylic (MemoryLens, 8%; Hydroview, 4%) and silicone (CeeOn 920, 4%; CeeOn 911A, 0%) (P =.0044). In all cases, the cellular reaction was low grade and clinically insignificant. Regarding capsular biocompatibility, some eyes developed lens epithelial cell (LEC) outgrowth on the anterior IOL surface. The highest incidence was in the hydrophilic acrylic group (Hydroview, 85%; MemoryLens, 27%) followed by the hydrophobic acrylic (AcrySof, 4%; AR40, 3%). No silicone IOL had LECs on the anterior surface. The difference among IOL groups was significant (P =.0001). Anterior capsule opacification was more predominant in the hydrophobic IOL groups. Posterior capsule opacification of the central 3.0 mm area was lowest in the groups with a sharp-edged optic (CeeOn 911A, AcrySof) followed by the round-edged silicone (CeeOn 920), hydrophobic acrylic (AR40), and hydrophilic acrylic IOLs (P =.0001). There was a significant difference in flare between the AR40 lens and the Hydroview, MemoryLens, CeeOn 911A, and CeeOn 920 (P <.004). There was no statistically significant difference in the postoperative cell count at 1 year. The power calculation showed that the sample size was sufficient. CONCLUSIONS: The differences in cellular reaction, although clinically mild in normal eyes, indicate that there were more giant cells with hydrophobic acrylic IOLs and an increased tendency toward LEC outgrowth with hydrophilic lenses. The incidence of PCO was lowest in the hydrophobic IOL groups, especially in groups with a sharp-edged optic. Second-generation silicone IOLs with a sharp edge had good uveal and capsular biocompatibility 1 year after surgery.     

Position of anterior capsulorhexis and posterior capsule opacification

PURPOSE: To evaluate whether the position of the anterior continuous curvilinear capsulorhexis influences the rate of posterior capsule opacification (PCO). METHODS: A total of 119 patients, aged 61-86 years, underwent cataract surgery with phacoemulsification performed by a single surgeon. The patients were randomized to implantation with either a silicone intraocular lens (IOL) (SI40NB, Allergan) or an AcrySof IOL (MA60BM, Alcon). Three years after surgery, the rate of PCO was analysed using the evaluation of posterior capsule opacification computer software (EPCO). The results were related to the capsulorhexis position, which was assessed with a retroillumination photograph. RESULTS: If the capsulorhexis was located partially or completely off the optics of the IOL, compared to totally on the IOL, significantly more PCO was found (p = 0.0014). When comparing within each IOL type, patients with AcrySof IOLs were found to have significantly less PCO when the capsulorhexis was totally on the optic (p = 0.0048). This difference was also significant in the silicone group (p = 0.041). CONCLUSION: A relatively small and central capsulorhexis allowing for the complete covering of the IOL optics by the rhexis edges seems to protect against PCO in cataract surgery, with both round-edged silicone IOLs and sharp-edged hydrophobic acrylic IOLs.     

Elapsed time for capsular apposition to intraocular lens after cataract surgery

OBJECTIVE: To examine when the anterior and posterior lens capsule completely become apposed to optics of silicone and acrylic intraocular lenses (IOLs) implanted after cataract surgery and to determine whether the different IOL materials influence the timing of completion of capsular contact. DESIGN: Randomized controlled clinical trial. PARTICIPANTS: Seventy eyes of 70 patients who were scheduled to undergo cataract surgery were randomly assigned to two groups using random number tables based on the type of IOL implanted: silicone or acrylic. Thirty-two patients in each group completed the follow-up. INTERVENTION: All eyes underwent phacoemulsification surgery with implantation of either a silicone or acrylic IOL. All IOLs were accurately placed into the capsular bag. MAIN OUTCOME MEASURES: Contact of the anterior and posterior lens capsule with the IOL optic surface was evaluated using the Scheimpflug videophotography system at 3, 5, 7, 9, 11, 14, 21, and 28 days after surgery. The postoperative day at which each capsule was completely apposed to the IOL optic was determined. In addition, anterior chamber depth was also measured. RESULTS: The anterior capsule was in contact with the IOL optic on the same day or earlier than the posterior capsule in all patients. Complete apposition of the IOL was observed significantly earlier with silicone IOLs than with acrylic IOLs with both the anterior capsule (6.2 versus 3.6 postoperative days; P < 0.0001) and the posterior capsule (11.1 versus 7.4 postoperative days; P = 0.0339). No significant change in mean anterior chamber depth was observed with the silicone IOL, whereas there was significant anterior shift after implantation of the acrylic IOL. CONCLUSIONS: Capsular contact with the IOL optic is completed within approximately 8 days after cataract surgery with silicone IOLs and 11 days with acrylic IOLs. Complete apposition to both the anterior and posterior capsule was significantly earlier with silicone IOLs than with acrylic IOLs.     

Preventive effect of a second-generation silicone intraocular lens on posterior capsule opacification

PURPOSE: To compare the preventive effect of a second-generation silicone intraocular lens (IOL) on posterior capsule opacification (PCO) with that of a soft acrylic IOL. SETTING: Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan. METHODS: After phacoemulsification, a silicone IOL (PhacoFlex II) was implanted in 1 eye and an acrylic IOL (AcrySof) in the contralateral eye of 5 rabbits. RESULTS: The posterior view 3 weeks after surgery showed slightly more PCO in 3 eyes with the PhacoFlex II lens than in eyes with the AcrySof IOL, with the PCO obscuring the iris structures. In 2 eyes with an AcrySof IOL, slightly more PCO was seen. Histopathological examination revealed that a bend and complex folds in the posterior capsule were formed with both the PhacoFlex II and AcrySof IOLs. However, the capsular bend formed by the PhacoFlex II lens, which was caused by its blunt edge, was not as sharp as that with the AcrySof IOL and more PCO was seen in all eyes with a PhacoFlex II lens. CONCLUSIONS: Capsular bend formation does not necessarily require a sharp optic edge. A truncated optic rim of a certain thickness appears to form a bend. The capsule-bending does not appear to be an all-or-nothing effect. There seems to be a transition. That a capsular bend forms despite a blunt rather than a sharp optic edge may explain why the second-generation PhacoFlex II IOL prevents PCO better than first-generation and PMMA IOLs.